This paper explains the functionality of the Robust tool. The Robust tool determines by means of a mathematical representation the model of the set of uncertainties, managing to establish uncertainty and performance functions. The main aim is to design four types of controllers and to evaluate the hardiness (stability and performance) of the closed loop system. Robust tool calculates the controller, the linear transformation fractional between the process and the disturbances, and it generates the graph of the Singular Value Structured µ of Robust Performance (RP), Robust Stability (RS) and Nominal Performance (NP).